The present invention relates to mixing machines in which solids carried in portable containers may be mixed while in their containers.
The invention is especially suitable to dry mixing of powders or other solids in a portable container in which the solids may be transported. These containers may be shipping containers or process containers in which the solids are transported in the course of batch processing operations. Liquids may also be mixed with the powders or other solids in a machine embodying the invention.
The mixing of materials is usually carried out with the aid of a separate mix tank or vessel. This tank may be rotated and oscillated (see U.S. Pat. No. 1,143,268 of June 15, 1915). It has also been the practice to mix liquids, usually paint, in their shipping cans through the use of shaker machines (see U.S. Pat. Nos. 1,429,652 of Sept. 19, 1922, RE 21,973 of Dec. 9, 1941; 2,323,403 of July 6, 1943; and 2,527,556 of Oct. 31, 1950). Such shakers are used with small cans. Where large containers carry the materials to be mixed, problems are presented in loading and unloading the containers from the mixing machine and in securely holding the containers so that they can be revolved and held at selected angles of inclination which facilitate solids mixing and blending. To solve these problems containerized mixing machines have used cradles for holding containers (see U.S. Pat. No. 2,868,519 of Jan. 13, 1959). Other approaches have been the use of containers having specialized wall structure (see U.S. Pat. No. 4,050,580 of Sept. 27, 1977). In order to tilt the container gimbal-like structures have been used (see U.S. Pat. No. 2,868,519 and 4,050,580). In one dry mixing machine marketed by Hoover Ball and Bearing, a cradle for the container is mounted in trunnions held on a superstructure which is tilted about one end. The cradle arrangements are difficult to load since there is limited accesss to the cradle. Loading and unloading is still further complicated by the trunnion design in that the trunnions and their superstructure can interfere with the lift truck unless great care is exercised. Moreover, the trunnion design is not well adapted for the selection of different angles of inclination or tilt which are needed for optimum mixing of different solids, for example powders of different materials and fineness.
Accordingly it is an object of the present invention to provide an improved machine for mixing solids in portable containers which has an assembly of elements integrated with each other so as to facilitate loading and unloading of the containers into the machine so that they can be revolved to mix the solids and tilted to selected angles of inclination.
It is another object of the invention to provide an improved containerized solids mixing machine having a driving station where the containers are revolved so as to mix the solids therein and in which the containers may be tilted to selected angles of inclination wherein the means for holding and tilting the containers are arranged in a manner which conserves the use of factory floor space.
It is a further object of the present invention to provide an improved machine for mixing solids while in portable containers by revolving the containers which enable the containers to be held securely without the need for special appliances such as cradles and bands although permitting the use of such appliances, if desired.
It is a still further object of the present invention to provide an improved machine for mixing solids while in portable containers by revolving the containers wherein the containers are held essentially entirely by compressive forces applied from the top and bottom to the side walls thereof where the containers are structurally the strongest.
It is a still further object of the present invention to provide an improved machine for mixing solids in portable containers which has a driving station where the loading of containers and the driving and tilting thereof is carried out at opposite ends of the station to permit more efficient operation.
It is a still further object of the invention to provide an improved machine for mixing solids in their portable containers in which the driving elements, such as motors and gears are enclosed and located away from the containers.
It is a still further object of the invention to provide an improved machine for mixing solids in portable containers which can handle containers of very large size, say 60 to 100 cubic feet capacity.
It is a still further object of the present invention to provide an improved machine for mixing solids in portable containers which can be provided with means for revolving the container about a vertical axis as well as a horizontal axis and with means or tilting the container about another horizontal axis which is mutually perpendicular to the axis about which the container is revolved.
It is a still further object of the present invention to provide an improved containerized solids mixing machine which can be manufactured at lower cost than other machines which attempt to provide operating features similar thereto.
Briefly described, a solids mixing machine embodying the invention is designed for use with portable containers in which the solids to be mixed are carried. The machine has a base and a drive station. The drive station has a housing. A holding mechanism removably secures the containers to the housing. The holding mechanism is rotatably mounted to the housing at one end of the housing. Motor means in the housing rotate the holding mechanism so that the mechanism and the containers are revolved about a generally horizontal axis. The entire drive station is pivotally mounted on the base which may be arranged to provide a stanchion in which the drive station is journalled along an axis generally perpendicular to the axis about which the container and the holding mechanism are revolved. In order to tilt the drive station for selecting the angle of inclination of the container which is desired to improve the mixing action for the particular solids therein, means, such as actuators connected between the base and the housing are provided. These actuators operate to pivot the entire drive station. The location of the holding mechanism at one end, which may be the front end, of the machine provides access almost entirely around the front end of the machine for loading and unloading. The housing is on the opposite side of the pivot mounting from the container holding mechanism. This enables the machine to be counterbalanced. The housing may be an enclosure for the motors and thus protects the containers as well as assisting in reducing the emission of noise from the machine. The assembly is of compact design thus making efficient use of floor space in the factory. The design is also adapted for use with containers having a large range of sizes and models of the same design as handle relatively small containers (e.g., 1 cubic foot) may be constructed of large size to handle very large containers (e.g., 100 cubic feet).